{"product_id":"samson-740951","title":"Samson PumpMaster 3 55:1 Packing Set \u0026 O-Ring Repair Kit (GK2) #740951","description":"\u003cdiv class=\"gleam-quick-specs\" style=\"background:#f5f5f5;border-radius:5px;padding:16px 20px;margin:0 0 16px 0;font-family:Roboto,sans-serif;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#283c92;font-size:16px;margin:0 0 8px 0;border-bottom:2px solid #283c92;padding:0 0 6px 0;\"\u003eQuick Specs\u003c\/div\u003e\n\u003cdiv class=\"gleam-tablewrap\" style=\"overflow-x:auto;margin:0;padding:0;\"\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;border-spacing:0;font-size:14px;margin:0;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:7px 12px;font-weight:600;color:#283c92;width:45%;\"\u003ePart Number\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003e740951\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef0f9;\"\u003e\n\u003ctd style=\"padding:7px 12px;font-weight:600;color:#283c92;\"\u003eKit Number\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003eGK2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:7px 12px;font-weight:600;color:#283c92;\"\u003eKit Type\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003ePacking Set Repair Kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef0f9;\"\u003e\n\u003ctd style=\"padding:7px 12px;font-weight:600;color:#283c92;\"\u003eIncluded Positions\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003e21–24\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:7px 12px;font-weight:600;color:#283c92;\"\u003eIncludes\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003eO-Ring #21 and Packing Set Components #22–24\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef0f9;\"\u003e\n\u003ctd style=\"padding:7px 12px;font-weight:600;color:#283c92;\"\u003eFits\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003eSamson PumpMaster 3 55:1 Grease Pumps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:7px 12px;font-weight:600;color:#283c92;\"\u003eApplicable Pump Models\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003e300, 302, 304\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef0f9;\"\u003e\n\u003ctd style=\"padding:7px 12px;font-weight:600;color:#283c92;\"\u003eService Manual\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003e840803 \/ SM840803\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"gleam-description\" style=\"font-family:Roboto,sans-serif;color:#333;max-width:900px;\"\u003e\n\u003ch2 style=\"color:#283c92;font-size:18px;margin:0 0 10px;\"\u003eSamson PumpMaster 3 55:1 Packing Set \u0026amp; O-Ring Repair Kit (GK2) #740951\u003c\/h2\u003e\n\n\u003cp style=\"font-size:14px;line-height:1.7;\"\u003eSamson #740951, also identified as repair kit \u003cstrong\u003eGK2\u003c\/strong\u003e, is the packing-set service kit for PumpMaster 3 55:1 air-operated grease pumps. Samson's service manual lists GK2 as the \u003cstrong\u003ePacking Set\u003c\/strong\u003e repair kit and identifies it as covering pump positions 21 through 24.\u003c\/p\u003e\n\n\u003cp style=\"font-size:14px;line-height:1.7;\"\u003eThe service procedure confirms that these components include the O-ring at position 21 and the packing-set components at positions 22 through 24. They seal the area between the air-motor and fluid sections of the pump and are replaced together during the packing repair procedure.\u003c\/p\u003e\n\n\u003ch3 style=\"color:#283c92;font-size:15px;border-bottom:2px solid #283c92;padding-bottom:6px;margin:16px 0 8px;\"\u003eWhen This Kit May Be Needed\u003c\/h3\u003e\n\n\u003cp style=\"font-size:14px;line-height:1.7;\"\u003eSamson's troubleshooting information identifies worn or damaged seals at positions 22 and 23, or damage to O-ring #21, as possible causes of grease bypassing into the air motor. These components are included in GK2.\u003c\/p\u003e\n\n\u003cul style=\"font-size:14px;line-height:1.7;margin-top:0;\"\u003e\n\u003cli\u003eGrease has bypassed into the air-motor section\u003c\/li\u003e\n\u003cli\u003ePacking components #22 or #23 are worn or damaged\u003c\/li\u003e\n\u003cli\u003eO-ring #21 is worn, damaged, or incorrectly positioned\u003c\/li\u003e\n\u003cli\u003eThe pump is being serviced according to Samson's packing-set repair procedure\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp style=\"font-size:14px;line-height:1.7;\"\u003eA leak at the air outlet muffler can have more than one cause, so use the Samson troubleshooting procedure to identify the failure before replacing parts.\u003c\/p\u003e\n\n\u003ch3 style=\"color:#283c92;font-size:15px;border-bottom:2px solid #283c92;padding-bottom:6px;margin:16px 0 8px;\"\u003eKit Contents\u003c\/h3\u003e\n\n\u003ctable style=\"width:100%;border-collapse:collapse;border-spacing:0;font-size:14px;margin:0 0 16px;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#283c92;color:#fff;\"\u003e\n\u003ctd style=\"padding:8px 12px;font-weight:600;\"\u003ePosition\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;font-weight:600;\"\u003eComponent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003e21\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003eO-Ring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef0f9;\"\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003e22–24\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;\"\u003ePacking Set Components\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3 style=\"color:#283c92;font-size:15px;border-bottom:2px solid #283c92;padding-bottom:6px;margin:16px 0 8px;\"\u003eInstallation Notes\u003c\/h3\u003e\n\n\u003cp style=\"font-size:14px;line-height:1.7;\"\u003eSamson instructs technicians to remove the existing packing set at positions 22–24 and O-ring #21, replace those components, and clean the O-ring seat before reassembly.\u003c\/p\u003e\n\n\u003cp style=\"font-size:14px;line-height:1.7;\"\u003e\u003cstrong\u003eAssembly order is important:\u003c\/strong\u003e install O-ring #21 in its correct position inside the motor body first, followed by the large packing set and then the small packing set.\u003c\/p\u003e\n\n\u003cp style=\"font-size:14px;line-height:1.7;\"\u003eFollow Samson service manual 840803 for complete disassembly, pressure-relief, cleaning, inspection, and reassembly instructions.\u003c\/p\u003e\n\n\u003ch3 style=\"color:#283c92;font-size:15px;border-bottom:2px solid #283c92;padding-bottom:6px;margin:16px 0 8px;\"\u003ePump Compatibility\u003c\/h3\u003e\n\n\u003cp style=\"font-size:14px;line-height:1.7;\"\u003eThe PumpMaster 3 55:1 family includes Samson pump models #300, #302, and #304 for 35 lb, 120 lb, and 400 lb grease containers. The pump family is designed for grease up to NLGI-2 and uses a 55:1 pressure ratio.\u003c\/p\u003e\n\n\u003ch3 style=\"color:#283c92;font-size:15px;border-bottom:2px solid #283c92;padding-bottom:6px;margin:16px 0 8px;\"\u003eRelated PumpMaster 3 Repair Kits\u003c\/h3\u003e\n\n\u003cul style=\"font-size:14px;line-height:1.7;margin-top:0;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003e#740950 (GK1):\u003c\/strong\u003e Air motor repair kit, positions 1–20\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e#740952 (GK3):\u003c\/strong\u003e High-pressure valve repair kit, positions 25–28\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e#740953 (GK4):\u003c\/strong\u003e Foot valve repair kit, positions 30 and 35–38\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e#740954 (GK5):\u003c\/strong\u003e Pressure check valve, high-pressure cylinder and piston kit, positions 25–34\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"background:#eef0f9;border-radius:5px;padding:16px 20px;margin:16px 0;\"\u003e\n\u003cp style=\"margin:0;font-size:14px;\"\u003eNot sure GK2 is the correct repair kit for your PumpMaster 3? Call Alamo Equipment at \u003ca href=\"tel:+18178653707\" style=\"color:#283c92;font-weight:600;\"\u003e(817) 865-3707\u003c\/a\u003e and we can help match the pump symptom to the appropriate Samson repair kit.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cp style=\"font-size:13px;color:#555;\"\u003e\u003cstrong\u003ePart numbers:\u003c\/strong\u003e 740951, GK2\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cstyle\u003e\n.gleam-quick-specs .gleam-tablewrap,\n.gleam-quick-specs .table-wrapper,\n.gleam-quick-specs table,\n.gleam-quick-specs tbody,\n.gleam-quick-specs tr{\nmargin:0!important;\npadding:0!important;\nheight:auto!important;\n}\n.gleam-quick-specs{padding:16px 20px!important;}\n.gleam-quick-specs table td,\n.gleam-quick-specs table th{\npadding:7px 12px!important;\nline-height:1.35!important;\nheight:auto!important;\nvertical-align:middle!important;\n}\n\u003c\/style\u003e","brand":"Samson","offers":[{"title":"Default Title","offer_id":54447045116197,"sku":"ALMSAM740951","price":53.1,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0758\/0037\/9685\/files\/Samson_OEM-Part.jpg?v=1787192936","url":"https:\/\/alamoequipment.com\/products\/samson-740951","provider":"Alamo Equipment","version":"1.0","type":"link"}